1. Field of the Invention
This invention relates to surgical tissue augmentation in general and more specifically to methods and apparatus for surgical treatment of urinary incontinence by augmentation of the the bladder neck, the periurethral and sphincteric tissues near the bladder neck, the submucosal tissues of the urethra, or the tissues adjacent to the urethra.
2. Description of the Related Art
Millions of people suffer from urinary incontinence, which is the inability to voluntarily retain the urine in the bladder until release is appropriate. Although women are more likely to experience incontinence than men, the condition can affect either males or females of any age. A few of the common causes of incontinence are stroke, multiple sclerosis, prostate surgery, complications of chilbirth, and age. The problem often arises due to problems with the muscles that surround the urethra and retain the urine in the bladder. Many types of urinary incontinence are known, classified, and treated by a variety of methods, some surgical and some non-surgical.
Among the surgical procedures for incontinence are various types of implants: both implantable devices and materials for tissue augmentation. U.S. Pat. No. 5,562,598, for example, discloses an implantable device including a urethral cuff, a connecting tube, and an elastomeric bellows assembly. The device is closed by an external magnet placed on the skin over the implanted reservoir assembly. When the external magnet is in place the elastomeric bellows of the reservoir are compressed, and the prosthetic sphincter is closed. Removal of the external magnet from the skin over the implant allows the bellows to expand, thus opening the urethral cuff.
The magnetic device of U.S. Pat. No. 5,562,598 is obviously somewhat complex, and less convenient than normal voluntary control over the flow of urine. Indeed, any externally actuated device (and many are available) is inconvenient, undignified, and potentially embarrassing.
Many if not most patients would prefer a surgical method which would restore their normal ability to control urinary function through muscular contraction. Toward that end, procedures are available which employ tissue augmentation or “bulking” of the periurethral and sphincteric tissues near the bladder neck. For example, a collagen product sold under the trademark, “Contigen” is available. U.S. Pat. No. 6,277,392 to Klein (Aug. 21, 2001) describes a carbon-based biocompatible material for tissue augmentation of the tissues around the urethra. Small implantable devices such as that described in U.S. Pat. No. 6,231,501 to Ditter (May 15, 2001) are also known for enhancing a patient's ability to achieve voluntary muscular closure of the bladder outlet. Periurethral injection of Polytetrafluoroethylene (PTFE) has a known use in cosmetic enhancement surgery, see U.S. Pat. Nos. 5,607,477; 5,782,913; and 5,941,913 to Schindler et al. This material also shows promise as a method for bulking the tissues around the urethra.
One known method for urethral bulking employs an expanded polytetrafluoroethylene (PTFE) tubing. This tubing can be delivered into the periurethral tissue to augment the natural contraction of the urethral sphincters, thus aiding in bladder control. However, delivery of this material can be time consuming and difficult to control.